1. The mechanical timer assembly2. The parachute suspension system3. The out-of-line igniter4. The case assembly with the tamped candleThe mechanicaltimerassembly consists of amechanical timer and related hardware in a Lexanplastic housing. The nonexplosive mechanical timerfunctions like the explosive Mk 364 fuze on the Mk 45flare. The mechanical timer is a three-gear timer,powered by a torsional mainspring. A phosphorescentplastic decal with calibrated markings from 250 to11,000 feet of fall is located on the face of the timercover. A white, plastic, dial timer knob is used to set thedesired drop distance. Settings of 150,500, and 1,000to 11,000 feet can be selected. A safe setting is alsoprovided.An 18-foot diameter cruciform-shaped canopyparachutesuspensionsystemis used for goodstability. The riser cables connect the parachute toa bulkhead. The bulkhead separates the parachutecompartment from the remainder of the flareassembly. One cable is attached to an explosive bolt forparachute dump at candle burnout, just like the Mk 45flare.In the ignitionsystem, a lanyard is attached to oneof the parachute riser cables. This lanyard is threadedthrough the bulkhead and past the candle in an internalraceway along the side of the aluminum case. This leadsto the ignition assembly in the ignition housing near thecandles face. The lanyard is attached to a triggeringmechanism, which consists of the out-of-line igniter(OLI-2/A). Upon ignition, the firing pin initiates thepyrotechnic firing train.The aluminum caseassembly contains a tamp-castilluminating candle that consists of a composition ofmagnesium, sodium nitrate, and a polymer binder. Theflare is designed so the outer aluminum case is partiallyconsumed during candle burning.OperationA lanyard is attached to the timer knob on the flaretimer during flare uploading procedures. The lanyard isalso connected to the flare drogue tray or bomb rack,depending on the launch configuration. At launch, thetimer knob is pulled out of the timer (requiresapproximately 30 pounds of force) by the lanyard,starting the clock mechanism. After the preset time(drop distance) ends, the three locking pawls in the timerassembly release, retracting and releasing the timerassembly. A spring, located between the timer assemblyand the packaged parachute, expels the timer assembly,which, in turn, initiates removal of the parachute fromthe flare case. When the cord breaks, it separates thetimer assembly from the parachute. As the parachutesystem deploys and its main cables are pulled taut, theignition lanyard is pulled to activate the ignition system.The ignition lanyard must exert a pull force in excess of90 pounds to pull the slider assembly in line. This, inturn, releases the firing pin against the primer. Theprimer ignites a propellant wafer that producessufficient heat for candle ignition. Pressure buildupduring candle ignition blows off the igniter housing, andthe candle power reaches a nominal value. Just beforecandle burnout, the explosive bolt functions to releaseone of the suspension cables, causing the parachute todump.The LUU-2B/B flare has several advantages overthe Mk 24 and Mk 45 flares. The most importantadvantage is that the candle is not ejected from thecase on the LUU-2B/B. Only the parachute is removedfrom the case. This is accomplished by a mechanicaltimer instead of an explosive fuze, as is done in theMk 24 and Mk 45. Therefore, if the timer knobshould be accidentally pulled during handling whenthe timer is not on the SAFE setting, the timer andrelease mechanisms can be forcibly hand-held ontothe flare housing to prevent ejection of the timer andrelease mechanisms. When the timer completes itscycle, the timer mechanism can be taped on the flarehousing and marked for disposal. If the timer isejected from the flare and a portion of the parachutecomes out of the housing, the parachute can bestuffed back into the housing, taped, and marked fordisposal.Another advantage of the LUU-2 B/B flare is theincreased pull force on the parachute lanyard to initiatethe ignition sequence.If the parachute shouldaccidentally deploy on the flight deck/line, the openingshock from deck winds or jet blast is not sufficient toignite the candle.REVIEW NUMBER 2Q1. What is the length and diameter of the Mk 45Mod 0 aircraft parachute flare ?Q2. What fuze is used with the Mk 45 Mod 0 flare?Q3. What are the settings of the Mk 45 Mod 0 flare?Q4. List the component that holds the dial indicatorat a selected setting or at SAFE.4-8